Interval timer control circuit for a two speed motor



April 26, 1966 J. BowMAN 3,248,632

INTERVAL TIMER CONTROL CIRCUIT FOR A TWO SPEED MOTOR Original FiledApril lO, 1961 7 l /418 @im r 341/ l 412 I @l I i? 5a; ff f' @w -O-T* Is; j `7J`Wf4 i l fa" i 44 l I i n mmf-,91ML WM5 I l J f MASTER ji] 479 4INVENTOR. Jbe 50a/man A TT ORNE YS United States jatent 3,248,632INTERVAL THMER CONTROL CIRCUIT FOR A TWO SPEED MGTGR Joe Bowman,Greentown, Ind., assigner to Kingston Products Corporation, Kokomo,Ind., a corporation of indiana Urignal application Apr. 10, 1961, Ser.No. 101,933, now Patent No. 3,185,867, dated May Z5, 1965. Divided andthis application Sept. 16, 1964, Ser. No. 396,966

9 Claims. (Cl. 318-447) This invention relates generally to time delaymeans, and more specifically to an improved electrical circuit embodyingtime delay means.

This application is a division of my oopending application, Serial No.101,933, filed April l0, 1961, now U.S. Patent No. 3,185,867.

Although the principles of the present invention ymay be included invarious devices or circuits, a particularly useful application is madein a time delay circuit for a laundry machine, such as an automaticwashing machine of the home laundry type. Typical machines of this typeinclude a two-speed motor which, along with other components, isoperated by a master timer in accordance with a predetermined program orcycle. The user of such a device may manually interrupt the cycle at anytime to add to or to remove from the number of articles being cleansed,or to inspect the same. Not all points within the program represent apeak load on the machine, and in certain instances if the machine isstopped under a peak load condition, subsequent restarting thereof undersuch peak load condition could be abortive, or could be damaging to thetwo-speed motor.

The present invention contemplates the utilization of time delay meanswhich are set into operation automatically to modify the peak loadcondition temporarily to be a no-load or a low-load condition, afterwhich the regular program cycle is resumed.

Accordingly, it is an object of the present invention to provideimproved electrical time delay means.

Another object of the present invention is to provide an improved timedelay circuit for protecting a motor.

A still further object of the present invention is to provide time delaymeans which are automatically responsive to a predetermined condition.

Yet another object of the present invention is to provide time delaymeans in a circuit for protecting a device against initiation ofoperation thereof under peak load conditions.

A still further object of the present invention is to protect thetwo-speed motor of a laundry machine against overload arising out ofattempted starting of the same by means of the high-speed windingthereof.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description and the accompanying sheet ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is `shown by way of illustrativeexample.

On the drawings:

FIGURE 1 is a schematic diagram of a time delay circuit and mechanismprovided in accordance with the principles of the present invention; and

FIGURE 2 is a schematic fragmentary diagram illustrating a modified formof reset mechanism.

As shown on the drawing:

The principles of this invention are particularly useful when embodiedin time delay means such as illustrated in FIGURE 1, generally indicatedby the numeral y10. The time delay means 10 includes a circuit havingone or more devices 11, 12, the operation of which is normally icecontrolled by a master timer 13, the time delay circuit including aninterval timer 14 connected between the master timer 13 and the loaddevices 11 and 12.

The instant invention is used to advantage in a laundry machine, such asan automatic washing machine, where the device 11 comprises a two-speedmotor, and the device 12 comprises a spin control solenoid. The motor 11is the main drive motor for such washing machine in this illustration,and typically includes two main windings 15, 16. The motor 11 isconventional and has a conventional starting winding and switchassociated withthe main winding 15, which have been omitted from thedrawing since the same are known in the art. By way of example, thewinding 15 may be disposed upon four poles, and for purposes ofidentilication, is referred to herein as a highspeed winding. Thewinding 16 may comprise a larger number of poles, for example six poles,and is referred to herein as a low-speed winding. Thus, each of thewindings 15 and 16 comprises a load circuit, only one of which isenergized at a time so as to obtain a relatively low or a relativelyhigh speed of motor rotation. Also included in the motor 11 is acentrifugal switch 17 which has a tenminal or contact 18 continuallyconnected to the high-speed winding 15, a terminal or contact 19continually connected to the low-speed winding 16, and a centrilicallyresponsive contact 2t) which engages the Contact 18 when the mot-or isstationary, and which is thus normally closed therewith. The contact 20is engageable with the contact 19 whenever the motor speed reaches apredetermined cutover speed which is below the ultimate speed that the-motor would obtain if the motor 11 were continually energized throughthe high-speed winding 15.

The device 12, represented as a solenoid, is typicalof other componentswhich may be deenergized temporarily to minimize peak current values, inaccordance with this invention.

The master timer 13 which controls the various devices in the circuit,such as the load devices 11 and 12, is 0f conventional or knownstructure. Only so much of the master timer 13 is here illustrated as isnecessary for a full understanding of the present invention, and itincludes a timer motor 21 drivably connected to cam-means 22a, 22h, 22C,and 22d, the cam-means controlling the position of a number of switches23, 24, 25, and 26.

, The cam-means 22a-d haveA a periphery or contour or configurationrequired to achieve a desired program of control for the variouscomponents controlled thereby, the number and length of rises and fallsor highs and lows on such cam-means being a matter of choice to suit aparticular use.

In this embodiment, the master timer switches 23-26, are under thefurther control of a master switch 27, and more specifically, under thecontrol of the contacts 27a and 27b thereof.

A pair of lines 23 and 29 provide power to the circuit 10 for operationthereof. The operation of so much of the circuit as has been explainedis as follows. With the -master switch 27a, 27b closed as shown, poweris transmitted through a leadwire 30, through the timer switch 25 to thetimer switches 23 and 24. The timer switch 24 is thus capable ofproviding power through a pair of leads 31 and 32 to the solenoid 12. y

The timer switch 23 under the control of the cammeans 22a, is operativewhen in its lowest position to provide power through a leadwire 33 tothe high-speed winding 15. Thus the lower side of the switch 23, the Vleadwire 33, and the winding 15 jointly comprise a highspeed circuit,which thus has a portion in the master timer 13 and a portion in thetwo-speed motor 11. Thus when the switch 23 is in its lower position,the high-speed cir- 3 cuit is energized for obtaining operation of themotor 11 continuously at its higher speed.

Connected in parallel with the high-speed circuit 33 is a low-speedcircuit 34, 35, which includes a portion in the master timer 13 which isthe upper portion of the switch 23, and a portion in the two-speed motor11, which is the low-speed winding 16. It is to be noted that when thelow-speed circuit 34, 35 is energized, the same communicates Vinitiallyby means of the centrifugal switch 17 with the high-speed winding 15which with its aforesaid starting winding serves as a starting windingfor the lowspeed winding 16 under this condition, the switch 17 cuttingover to the low-speed winding 16 before the ultimate high-speed of thewinding 15 is obtained.

Assuming that the master timer 13 is in the position such as shown bythe solid lines, with power applied to the leadwires 28 and 29, it isapparent that the contacts 19 and 20 of the centrifugal switch 17 willbe ciosed, and that the motor will be driven at its lower speed.Likewise, the solenoid 12 will be energized. If, under this set ofconditions, the switch 27a, 27b is opened, it is apparent that all powerto the devices 11 and 12 will be interrupted, and when the contacts 27a,27h are reclosed, an extremely high and abnormal current load will beplaced on the lines 28 and 29. In a practical installation, thiscombination of conditions will occur when the mechanical load on thetwo-speed motor is relatively high,

thereby further aggravating the problem. The problem` -cur during acontrolled cycle if the operator wishes to add a garment to the load, toremove a garment from the load, or to inspect the progress or effect ofthe cycle on the load. Thus, a user may innocently open the door 37 andreclose it at a time when the mastertimer 13 is in such a position as tocall for the controlled devices to be energized while under high loadconditions.

In accordance with this invention, I have provided the interval timer 14which is responsive to a predetermined condition, such as the doorposition, to temporarily minimize or redistribute the load for a iixedpredetermined interval.

The interval timer 14 includes cam-means 33a, 38b, and 38e, collectivelyreferred to as cam-means 33, which may comprise any known structuralform. The cammeans 38 are driven by a timer motor 39 in the directionindicated by the arrows on the cams to the position illustrated in thedrawing. The interval timer 14 includes a normally open switch 40, anormally closed switch 41, a normally open switch 42, and a normallyclosed switch 43. The switch 43 is normally closed so that the switch 24can normally control the device 12. The switch 41 is normally closed sothat the upper portion of the switch 23 may normally control'thelow-speed circuit 34, 35. It is to be noted that the high-speed circuit33 includes no switch between the lower portion of the switch 23 and thecentrifugal switch 17, and thus physically the highspeed circuit 33 maybe disposed externally of the interval timer 14. y

To energize the interval timer motor 39, power is brought from themaster timer switch 25, through a lead 44, through the normally openswitch 40, and thence by a lead 45 to the motor 39, the other side ofthe motor 39 being connected to the leadwire 29. It is thus clear thatfor the position of the cam-means 38 illustrated, the motor 39 will notbe operating.

To shift the cam-means 38 to a position where the switch 40 will beclosed, there is provided a further contact 27C in the switch 27 whichis engaged by the contact 27a in response to door opening, therebyenergizing a leadwire 46 under the control of the master timer switch26, and leading to an electromagnetic actuator 47 which is alsoconnected to the line 29. The electromagnetic actuator 47 ismechanically connected as at 48 to movable means 49. A clutch 5t) has aside 51 connected to the cam-means 38, and another or opposite side 52connected to the movable means 49. Upon movement of the door 37 in anopening direction, the contacts 27a, 27C are closed, thereby energizingthe electromagnetic actuator 47 which mechanicaliy acts on the movablemeans 49 to rotate the side 52 of the clutch 50 in the direction of thearrow, which direction is opposite to that in which the interval timermotor 39 drives the cam-means 38. The clutch 50 transmits this movementto the cam-means 38 so as to simultaneously close the switches 4@ and42, and so as to simultaneously open the switches 41 and 43. When soshifted, the cam-means 38 are then disposed in a start position whichrepresents the start of the program or cycle controlled by the intervaltimer 14.

If desired, means may be provided to accurately define this startposition. To that end, I have illustrated means at 53 which are jointlymovable with the cam-means 33 and which are engageable with a stop 54when they have moved to the position indicated in broken lines, wherebya fixed starting position for the cam-means 38 and the switches 40-43 isdefined.

Upon reclosing of the door 37, power will be brought to the master timerswitch contacts 25, but the device 12 cannot be energized since thecontacts 43 are open. Power will also be brought through the switch 23in the master timer 13, it being i-n the upper position, to energize theleadwire 34, the same being a part of the low-speed circuit. However,the switch 41 is then open to preclude any application of power throughthe lead 35 to the contact 20 in the centrifugal switch 17, but power isdirected through the then closed switch 42 which has a connection 55with the high-speed circuit 33 to deliver power only to the high-speedWinding 15, the centrifugal switch 17 being by-passed. Thus, where thereis a high mechanical load on the two-speed motor 11, other loads aredeenergized, and the centrifugal switch 17 is by-passed so that thehigh-speed winding will remain energized even though the cutover speedof the centrifugal switch has been reached or exceeded. This conditionmay continue advantageously for any desired period of time after thecutover speed is normally reached, for example until the ultimate speedobtainable by the high-speed winding 15 is reached.

Closing of the switch contacts 27a, 27h also eifects delivery 0f powerthrough the leadwire 44, the now closed switch 40, and the leadwire 45,to the interval timer motor 39, thereby causing the cam-means to bedriven to the point where the cam-means 33a rc-opens the switch 4t),such point being herein referred to as the stop or finish position, asillustrated.

The specific configuration of the cam-means 38 illustrated herein, isunderstood to be entirely exemplary, it being understood that theeffective portion of the cammeans 38h and 33C is that which engages theswitch 'blades of the associated switches from the start to the finishposition. At any event, an appropriate predeter mined timing cycle isprovided on the cammeans 38 to insure obtaining of the required delay.By Way of example, the timer motor 39 may drive the cam-means, once itis energized at its start position, for nineteen seconds at which timethe switch 42 would reopen and the switch 41 reclose, the switch 43closing a second or two later, and the switch 40 opening a second or soafter all other switches in the interval timer have reached their iinishposition.

The switch contact 27e, the switch 26, the electromagnetic actuator 47,the mechanical connection 4S, and the movable means 49, or certainportions thereof, are

jointly referred tol herein as a reset mechanism. It is clear that thereset mechanism responds to each occurrence of a predetermined conditionwhich, in this instance, is the opening of the door 37. Every time thatthe door 37 opens with the switch 26 closed, the reset mechanism `movesthe interval timer to a start position, and it does so even if the door37 was opened at any point in the running of the cycle of the intervaltimer 14. Each such reopening insures that the full delay built into theinto the position shown in solid lines, the remaining portion of thedelay cycle will neverthelessV be provided so as not to overload themotor 11. Thus, the reset mechanism responds to each occurrence of thepredetermined condition,' namely the opening of the door, and the resetmechanism isalways operative when actuated to drive the carnmeans 3S ina direction opposite to that of the motor 39 by an amount which bringsthe engageable means 53 against the stop, any excess travel in theelectromagnetic actuator 47 being provided for by the clutch Si). Insummary, the opening of the door 37 is the predetermined condition whichelfects a resetting of the interval timer 14, while the closing of thedoor 37 is the predetermined condition which initiates operation of thetiming cycle of the interval or delay timer 14.

In certain instances, the mechanical connection 48 may be connecteddirectly to the door 37, thereby enabling the omission of contact 27C inswitch 27, line 46, cammeans 22d, switch 26, and the electromagneticactuator 47. Such a modification is illustrated in FIGURE 2 where themechanical connection 4S is shown in solid lines. The door 37 will, ofcourse, have the further mechanical connection 36 leading to the switch27, as shown in FIGURE 1.

Although various minor modications might be suggested by those versed inthe art, it should be understood that I wish to embody within the scopeof the patent warranted hereon, all such embodiments as reasonably andproperly come Within the scope of my contribution to the art.

I claim as my invention:

1. A circuit comprising in combination: a two-speed motor having alow-speed continuous duty winding and a high-speed continuous dutywinding; and an interval timer connected to said two-speed motor in suchmanner and having such means as to always complete the circuit onlythrough said high-speed winding for a predetermined limited period oftime, and thereafter operative to prepare completion of the circuit onlythrough said low-speed winding.

2. A circuit comprising in combination: a two-speed motor having alow-speed continuous duty winding, a high-speed continuous duty winding,and a centrifugal switch connected thereto, said switch normallycompleting the circuit through said high-speed winding from a stoppedposition to a cut-over speed below the ultimate high speed, and normallythrough said low-speed winding at speeds above the cut-over speed; andan interval timer connected to said two-speed motor in such manner andhaving such means as, when actuated, to break the circuit through saidcentrifugal switch, and to always complete the circuit through saidhigh-speed winding until said motor has reached a speed above saidcutover speed, and thereafter operative to prepare completion of thecircuit through said low-speed winding.

3. A circuit comprising in combination: a two-speed motor having alow-speed continuous duty winding, a

high-speed continuous duty winding, and a centrifugal switch connectedthereto, said switch normally completing the circuit through saidhigh-speed winding from a stopped position to a cut-over speed below theultimate high speed, and normally through said low-speed winding atspeeds above the cut-over speed; and an interval timer connected to saidtwo-speed motor in such manner and having such means as, when actuated,to break the circuit through said centrifugal switch, and to alwayscomplete the circuit through said high-speed winding until said motorhas reached a speed above said cut-over speed, and thereafter operativeto prepare completion of the circuit through said centrifugal switch andsaid low-speed winding. v v

4. A circuit comprising: a device having two alternatively energizablecontinuous duty load circuits; a master timer normally controllingcurrent for both of said load circuits and operative to energize onlyone of them at a time; and an interval timer connected between saidmaster timer and said load circuits, and operative,

When said master timer is calling for the energizing of only one of saidload circuits, to effect always, in response to each occurrence'of afurther predetermined condition, energization of only the other of saidload circuits for a predetermined interval, and thereafter operative toprepare completion of the circuit only through said one of said circuitsby restoring the control of said load circuits to said master timer.

5. A circuit for a laundry machine having a door, said circuitcomprising in combination: a motor having a low-speed continuous dutycircuit and a high-speed continuous duty circuit; a master timerconnected to be normally controlling current for both of said motorcircuits and operative to energize only one of them at a time; and aninterval timer connected in the laundry machine circuit ybetween saidmaster timer and said motor circuits, and operative, when said mastertimer is calling for energizing only said low-speed motor circuit,always to etect, in response to each opening and closing -of the machinedoor, energization of only said high-speed motor circuit i for apredetermined interval, and thereafter operative to prepare completionof the circuit only through said low speed winding, thereby restoringthe control of said motor circuits to said master timer.

6. A circuit for a laundry machine having a door, said circuitcomprising in combination: a motor having a lowv speed circuit and ahigh-speed circuit; a master timer connected to be normally controllingcurrent for both of said motor circuits and operative to energize onlyone of them at a time; a master switch adapted to be opened in responseto opening of the machine door and to interrupt current tlow to saidmot-or circuits in response to'such door opening; and an interval timerconnected in the laundry machine circuit between said master timer andsaid motor circuits, and operative, when said master timer is callingfor energizing only said low-speed motor circuit, to effect, in responseto such door opening, a connection with only said high-speed motorcircuit; said interval timer being operative in response to closing ofthe machine door and said master switch to energize said highspeed motorcircuit for a predetermined interval, and thereafter operative torestore the control of said motor circuits to said master timer.

7. A circuit for a laundry machine having a door, said circuitcomprising in combination: a two-speed motor; a master timer; alow-speed circuit having portions in said master timer and motor; ahigh-speed circuit having portions in said master timer and motor, andconnected in parallel with said low-speed circuit; said low-speed andhigh-speed circuits normally being controlled by said master timer, andonly one of said low and high-speed circuits being energizeable therebyat one time; and an interval timer having normally closed switch meansconnected in said low-speed circuit, said interval timer having meansrendering it responsive to a predetermined posi- 7 tion of the door;said interval timer being operative, when said means is `actuated bydoor movement, to open sai-d switch means and to interconnect the mastertimer portion of the low-speed circuit with the motor portion of thehigh-speed circuit for a predetermined interval, and to thereafterrestore the control of said low-speed circuit to said master timer.

8. A circuit for a laundry machine having a door, said circuitcomprising in combination: a motor having a lowspeed circuit and ahigh-speed circuit, said low-speed circuit being energizable by means ofa centrifugal switch driven by said motor, and being so energized onlyabove a predetermined motor speed, a master timer connected through saidcentrifugal switch to be normally controlling current for both of saidmotor circuits; a master switch adapted to be opened in response toopening of the machine door and to interrupt current ow to said motorcircuits in response to such door opening; and an interval timer havingcamoperated switches connected in the laundry machine circuit betweensaid master timer and said motor circuits, and having a reset mechanismoperative on said cam-operated switches in response to said opening ofthe machine door, when said master timer is calling for energizing onlysaid low-speed motor circuit, to effect, in response to such dooropening, a connection with only said high-speed motor circuit; saidinterval timer being operative in response to closing of the machinedoor and said master switch to energize said high- 9. A circuit for alaundry machine having a door, said circuit comprising in combination: atwo-speed motor; a double throw centrifugal switch; a master timer; alowspeed circuit having portions in said master timer, centrifugalswitch and motor; a high-speed circuit having portions in said mastertimer, centrifugal switch and motor, and connected in parallel with saidlow-speed circuit; said low-speed and high-speed circuits normally beingcontrolled by said master timer; and an interval timer having normallyclosed cam-operated switch'means connected in said low-speed circuit,said interval timer having reset means responsive to a predeterminedposition of the door; said interval timer being operative, when saidreset means is actuated by door movement, to open said camoperatedswitch means and to interconnect the master timer portion of thelow-speed circuit directly with the motor portion of the high-speedcircuit for a predetermined interval determined by said interval timer,and to thereafter restore the control of said low-speed circuit throughsaid centrifugal switch to said master timer.

References Cited by the Examiner UNITED STATES PATENTS 2,488,658 11/1949Brennan 318--225 X 2,502,823 4/1950 Clark 318-486 X 2,697,193 12/1954Jones B18-401 X 2,848,630 8/1958 MCNiCol et al. S18- 486 X 3,044,0007/1962 Bahra S18-486 X 3,148,321 9/1964 Holzer 318-486 ORIS L. RADER,Primary Examiner.

6. A CIRCUIT FOR A LAUNDARY MACHINE HAVING A DOOR, SAID CIRCUITCOMPRISING IN COMBINATION: A MOTOR HAVING A LOWSPEED CIRCUIT AND AHIGH-SPEED CIRCUIT; A MASTER TIMER CONNECTED TO BE NORMALLY CONTROLLINGCURRENT FOR BOTH OF SAID MOTOR CIRCUITS AND OPERATIVE TO ENERGIZE ONLYON OF THEM AT A TIME; A MASTER SWITCH ADAPTED TO BE OPENED IN RESPONSETO OPENING OF THE MACHINE DOOR AND TO INTERRUPT CURRENT FLOW TO SAIDMOTOR CIRCUITS IN RESPONSE TO SUCH DOOR OPENING; AND AN INTERVAL TIMERCONNECTED IN THE LAUNDRY MACHINE CIRCUIT BETWEEN SAID MASTER TIMER ANDSAID MOTOR CIRCUITS, AND OPERATIVE, WHEN SAID MASTER TIMER IS CALLINGFOR ENERGIZING ONLY SAID LOW-SPEED MOTOR CIRCUIT, TO EFFECT, IN RESPONSETO SUCH DOOR OPENING, A CONNECTION WITH ONLY SAID HIGH-SPEED MOTORCIRCUIT; SAID INTERVAL TIMER BEING OPERATIVE IN RESPONSE TO CLOSING OFTHE MACHINE DOOR AND SAID MASTER SWITCH TO ENERGIZE SAID HIGHSPEED MOTORCIRCUIT FOR A PREDETERMINED INTERVAL, AND THEREAFTER OPERATIVE TORESTORE THE CONTROL OF SAID MOTOR CIRCUITS TO SAID MASTER TIMER.